Effect of Oscillation Speed and Thrust Force on Cortical Bone Temperature During Sagittal Sawing

Author(s):  
Steven Micucci ◽  
Gerard Chang ◽  
Eric Smith ◽  
Charles Cassidy ◽  
Amrit Sagar ◽  
...  

Thermal necrosis of bone occurs at sustained temperatures above approximately 47°C. During joint replacement surgery, resection of bone by sawing can heat the bone above this necrotic threshold, thereby inducing cellular damage and negatively affecting surgical outcomes. The aim of this research was to investigate the effect of saw blade speed and applied thrust force on the heating of bone. A sagittal sawing fixture was used to make cuts in cortical bovine bone, while thermocouples were used to characterize the temperature profile from the cut surface. A full factorial Design of Experiments was performed to determine the relative effects of blade speed and applied thrust force on temperature. When comparing the effect of speed to force in the regression analysis, the effect of force on temperature (p < 0.001) was 2.5 times more significant than speed (p = 0.005). The interaction of speed and force was not statistically significant (p > 0.05). The results of this research can be used in the development of training simulators, where virtual surgeries with haptic feedback can be accompanied by the related temperatures in proximity to the cut. From a clinical perspective, the results indicate that aggressive cutting at higher blade speed and greater thrust force results in lower temperatures in the surrounding bone.

Author(s):  
Gerard Chang ◽  
Steven Micucci ◽  
Eric Smith ◽  
Charles Cassidy ◽  
Tobi Quinto ◽  
...  

A sagittal saw is used for resection of bone during joint replacement surgery. During sawing, tissue at the cut surface can be damaged by high temperatures, which may lead to aseptic loosening of implants. To date, there have been no studies relating sagittal sawing parameters to the level of tissue necrosis. The aim of this study was to determine the feasibility of using histopathological analysis in assessing the severity of thermal necrosis due to sawing. All sawing experiments were performed on cortical bone taken from fresh bovine femur. A two factor, two level design of experiments was performed looking at applied thrust force from 15 N to 30 N and blade oscillation speed from 12,000 cpm to 18,000 cpm. Each cut was subjected to standard histological preparation and the depth of empty lacunae was measured. Both experimental factors, force and speed, showed a statistically significant effect on the depth of thermal necrosis (p< 0.05). However, the interaction of speed and force did not prove to be statistically significant (p = 0.22). From a clinical perspective, the results indicate that choosing higher blade speeds and applying greater force can reduce the amount of thermal damage during sagittal sawing.


2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Marco S. Caicedo ◽  
Vianey Flores ◽  
Alicia Padilla ◽  
Samelko Lauryn ◽  
Joshua J. Jacobs ◽  
...  

Abstract Background Recent studies indicate that, in addition to antibody production, lymphocyte responses to SARS-CoV-2 may play an important role in protective immunity to COVID-19 and a percentage of the general population may exhibit lymphocyte memory due to unknown/asymptomatic exposure to SARS-CoV-2 or cross-reactivity to other more common coronaviruses pre-vaccination. Total joint replacement (TJR) candidates returning to elective surgeries (median age 68 years) may exhibit similar lymphocyte and/or antibody protection to COVID-19 prior to vaccination Methods In this retrospective study, we analyzed antibody titters, lymphocyte memory, and inflammatory biomarkers specific for the Spike and Nucleocapsid proteins of the SARS-CoV-2 virus in a cohort of n=73 returning TJR candidates (knees and/or hips) pre-operatively. Results Peripheral blood serum of TJR candidate patients exhibited a positivity rate of 18.4% and 4% for IgG antibodies specific for SARS-CoV-2 nucleocapsid and spike proteins, respectively. 13.5% of TJR candidates exhibited positive lymphocyte reactivity (SI > 2) to the SARS-CoV-2 nucleocapsid protein and 38% to the spike protein. SARS-CoV-2 reactive lymphocytes exhibited a higher production of inflammatory biomarkers (i.e., IL-1β, IL-6, TNFα, and IL-1RA) compared to non-reactive lymphocytes. Conclusions A percentage of TJR candidates returning for elective surgeries exhibit pre-vaccination positive SARS-CoV-2 antibodies and T cell memory responses with associated pro-inflammatory biomarkers. This is an important parameter for understanding immunity, risk profiles, and may aid pre-operative planning. Trial registration Retrospectively registered.


2015 ◽  
Vol 68 (1) ◽  
pp. 73-79 ◽  
Author(s):  
David J. Beard ◽  
Kristina Harris ◽  
Jill Dawson ◽  
Helen Doll ◽  
David W. Murray ◽  
...  

2015 ◽  
Vol 42 ◽  
pp. S32
Author(s):  
J.E. Naili ◽  
A.C. Esbjörnsson ◽  
M.D. Iversen ◽  
M.H. Schwartz ◽  
C. Häger ◽  
...  

Author(s):  
Sean S. Tolman ◽  
Amanda Beatty ◽  
Anton E. Bowden ◽  
Larry L. Howell

The parameters of an innovative padding concept were investigated using Finite Element Analyses (FEA) and physical testing. The concept relies on a compliant corrugation embedded in an elastic foam to provide stiffness for force distribution and elastic deformation for energy absorption. The shape of the corrugation cross section was explored as well as the wavelength and amplitude by employing a full factorial design of experiments. FEA results were used to choose designs for prototyping and physical testing. The results of the physical tests were consistent with the FEA predictions although the FEA tended to underestimate the peak pressure compared to the physical tests. A performance metric is proposed to compare different padding configurations. The concept shows promise for sports padding applications. It may allow for designs which are smaller, more lightweight, and move better with an athlete than current technologies yet still provide the necessary protective functions.


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